The basic idea is that your iPhone could continuously be taking photos while in camera mode. When you press the shutter button it could look back on its buffer of pictures and find the best one.
A method can include continuously capturing images with an image capturing device. The method can include storing a predetermined number of the sequence of images in a buffer. The device can receive a user request to capture an image. The method can automatically select one of the buffered images based on one or more parameters.
For example, the selection may be based on an exposure time of one of the buffered images and optionally an image quality parameter (e.g., image contrast). Alternatively, the selection may be based only on the image quality parameter. The sequence of images can be captured just prior to or concurrently with receiving the user request.
Read More [via AppleInsider]